If I remember correctly, Messiaen himself said something along the lines of Katsaris' Vingt Regards being the best performance he had ever heard...
I'm sorry; It's really unfair what I said concerning such a small portion of Vingt Regards. It was a stupid comment on my part. I'd love to hear the full performance.
Katsaris Messiaen's favorite? He may have said it, but I think he gave the same endorsement of Roger Muraro (who I've not heard), and I wouldn't be surprised if he said it also of Loriod, Aimard, Peter Hill, Peter Serkin, and others...I've heard the composer criticized for giving undue praise to anyone who touched his music (understand I'm not applying criticism to Katsaris in this statement).
Now, I do remember a great variety of profound liberties taken from performance to performance when comparing Yvonne Loriod's own output of live performances and recordings (and she truly owns the piece), and I'm sure Loriod was Messiaen's *true* favorite.

(My current favorite is Aimard in case you wonder.)
I love experiencing and comparing many, many performances, and I go through stretches with certain pieces that regardless of how good is the last performance I experienced, I want to experience it in a new performance. Katsaris is always someone to bring something different to the table whether it's an enlightening choice or not. I don't know if he's looking at a piece as an organic whole, or just trying to find more tricks for his magic show, but I suspect more often than not it is the later, but sometimes it results in the former (My favorite recordings of his are the Chopin Ballades). What I feared from the Messiaen clip was similar to the first impression I received from Michel Beroff's recording of the same...that more than using himself as a vehicle to bring to life a transcendent, ethereal work of art, he instead was using Vingt Regard to bring to life his outstanding virtuosity (a point of emphasis...and some wonder is there anything wrong with this? And I don't know!). I'm more than likely dead wrong in both cases (I now have good reason to revisit Beroff's recording!) I would *love* to hear Katsaris's performance.
(Phew...wordy...)